WASHINGTON (AP) — Hundreds of people have rallied outside the White House and President Donald Trump’s Washington hotel in a last-ditch effort to stop construction of the Dakota Access pipeline.

Participants in Friday’s march and rally say the protests against the pipeline have been successful even if it gets built because they’ve called attention to the issue of American Indian sovereignty.

A federal judge this week declined to halt construction of the final section of the $3.8 billion pipeline, meaning oil could begin flowing through it as early as next week.

The last pipeline section would pass under a reservoir that provides water to the Standing Rock Sioux.

The rally also revealed divisions among some activists. Standing Rock Sioux Chairman Dave Archambault II was booed and heckled by some in the crowd.